The present invention pertains to an apparatus for sealing a horizontally sliding gate which slides across the discharge opening of a railway hopper car, against the frame of said railway hopper car. When a hopper car is loaded with a fluidizing lading, such as fine particles of bauxite, bentonite, cement, flour, etc., problems are encountered with respect to that fluidizing lading sifting between the gate and the frame through the seal means. One solution to the sealing problem has to been to use gaskets, rubber or the like. However, if the gasket is to provide an effective seal, it must be securely pressed against the top surface of the gate around the entire peripheral thereof. Along with other problems, such as discussed in U.S. Pat. No. 4,253,400 to Fischer issued Mar. 3, 1981, there exists the problem that the discharge opening itself not be truly square. Additionally, since it is an integral part of the car, it may be warped and thus not square or flexed during a normal work cycle. These problems are typical in older railroad cars which are rebuilt and into which new horizontal sliding gate systems are incorporated in conjunction with a seal mechanism. Seal mechanisms, by their very nature, are subject to wear and a substantial number of clever mechanisms have been provided to lessen or minimize such wear. The wear does occur, however, and thus a method must be provided to replace the actual seal element, whatever it is. The sealing element, as well as the remainder of the seal mechanism, must be designed to allow a simple and convenient replacement of the old worn-out parts.
As compared to the prior art devices, the present invention provides a seal mechanism which compensates for a misaligned discharge opening, for flexing of the discharge opening during a work cycle, and when the inevitable occurs, for the actual and convenient removal and replacement of the pliable seal itself. In practice, the seal mechanism resembles a rectangular picture frame made up of separate flexible flange section means, which is secured in the discharge opening of the railroad hopper car. Around the entire periphery of the inside edge of the picture frame is a C-shaped channel. Carried within the C-shaped channel is a pliable seal means which in the preferred embodiment is a strip of nylon carpet wound around a steel rod. To achieve proper operation, it is important that the securement, in this embodiment, of the picture frame to the walls of the discharge opening be minimal. The welding need only be sufficient to hold the frame fixed within the discharge opening. I have found two welds on each side of the discharge opening a inch long to be sufficient. The seal mechanism is constructed in a manner and of a material which flexes to conform to the walls of the discharge opening and which when subjected to the weight of the lading is capable of bending and flexing allowing it to conform to the top of the discharge opening gate. As a result, there is substantial assurance that the seal has closed the opening when there is lading within the car. That is, the pliable sealing means (all four sides) are in a single first plane, parallel with but spaced away from a top or second plane swept out by the top surface of the slide gate. This result must be achieved irrespective of the relationship of the discharge opening walls to each other, to the rectangular picture frame and to the top surface of the slide gate. At the same time, when the car is empty and being moved from place to place, it is desirable that the pliable seal means is not in snug contact with the top surface of the horizontally sliding gate. Thus, the wear incident to the jarring and vibrations in the empty car are not present because the pliable seal floats slightly above, or at least has minimal contact with the top surface of the door.
Further objects and advantages will become apparent from the following description taken in conjunction with the drawings.